Finite element occupant models are used to predict the behavior of a vehicle occupant, such as a crash test dummy or a human, in a computer simulation of a vehicular accident. Computer simulation of a vehicular accident using finite element occupant models allows assessment of how a crash affects an occupant without requiring a physical crash test to be conducted. However, to provide accurate data, the finite element occupant model must be properly positioned before simulating a vehicle crash. Proper positioning ensures the finite element occupant model accurately reflects the positioning and behavior of a vehicle occupant, such as a crash test dummy or a human.
Currently, commercial software tools are used to position the finite element occupant model before simulating a vehicle crash. However, these existing software tools often inaccurately simulate joint movement by allowing components connected by a joint to interfere and penetrate each other. These “nodal penetrations” within the finite element occupant models cause the simulation to be inaccurate. These initial penetrations are caused by the existing software tools' inability to account for how real world joint motion deforms or modifies the regions surrounding the joint (e.g., movement of tissue surrounding the knee as the knee bends). To compensate for these nodal penetrations, conventional methods require manual removal of the nodal penetrations from the simulation, which is a time- and labor-intensive process.
Additionally, pre-simulating the position of the finite element occupant model is time-consuming and complicated by the risk of over-constraining the finite element occupant model's movement, causing erroneous pre-simulation results. As different components of the finite element occupant model are connected by joints, the relative motion of these connected components is restricted by the joints. Different types of joints (e.g., spherical, translational, planar, etc.) can be used to connect different components and each joint type differently constrains the relative motion of the connected components. Because component motion is constrained by the joint type, accurate simulation requires precise specification of how components move relative to each other, and inexact specification can cause unrealistic pre-simulation results. This precise description of motion requires time- and computation-intensive calculations.
Thus, there is a need for a method for positioning a finite element occupant simulation model which prevents nodal penetrations and unrealistic behavior modeling.